The following is a chapter from the book Mega
Brain, by Michael Hutchison. Mr. Hutchison also has another book, The
Book of Floating which is totally dedicated to the float tank.
ADRIFT ON THE GREAT LAKE OF UNKNOWING:
THE FLOTATION TANK
THE CASE OF THE INCREDIBLE DISAPPEARING BODY
Although modern flotation tanks make use of sophisticated technology, the
way they work is quite simple. Essentially, the tank is an enclosed container
about the size of a closet turned on its side. The vessel contains a shallow
pool of warm water (about 13 inches) in which over eleven hundred pounds
of Epsom salts have been dissolved, creating a solution so dense - far
more buoyant than the Dead Sea or Great Salt Lake - that anyone who lies
back in the water bobs on the surface like a cork. When the door is closed,
the tank is totally dark. This complete absence of external visual stimulation
is something most of us never experience in ordinary life situations, since
even in the darkest rooms, or on the darkest of nights, with our eyes tightly
closed, we still receive some ambient light. In the tank, it is impossible
to tell whether your eyes are open or closed. Immediately, that is, you
are in a visual blank-out.
Since your ears are underwater and stopped with plugs, there is also
an almost total absence of external sounds, another experience with no
counterpart in ordinary life situations. With this turning off of both
sight and sound, the float tank matches the blank-out effect created by
the unchanging ganzfeld and pink noise of the Tranquillity. However, the
tank goes beyond this by restricting stimuli reaching other senses as well.
The warm water of the tank is maintained at a constant temperature of about
93.8 degrees, which is equal to the body's temperature at the skin surface
- there is no feeling of either warmth or cold, so that you soon lose any
sense of separation between skin and water, and the boundaries of your
body seem to dissolve, effectively creating a blank-out of the sense of
touch, pressure, friction, and other skin sensations.
Another sensation floating turns off is the usually ever-present pressure
of gravity. In the words of the tank's inventor, neurophysiologist Dr.
John Lilly, "You're free of gravity; you don't have any more of those gravity
confrontations that you do all day long. Finding where gravity is, and
in what direction, and computing how you can move and not fall takes up
about 90 percent of your neural activity. As soon as you start floating
you're freed of all the gravity computations you've been doing all the
time, so you find you have a whole vast piece of machinery that was being
used for something else and you can now use it for your own purposes...
It's as if you are somewhere between the moon and the earth, floating,
and there is no pull on you. As soon as you move, of course, you know where
you are, but if you don't move your environment disappears and, in fact,
your body can disappear."
The tank, then uses technological means to quickly, easily, reliably,
and safely produce the turning off of the senses that all the meditative
techniques such as breath-counting, chanting, repetition of mantras, and
focused gazing strive for but so rarely attain. Even first-time floaters
find that within minutes they are suspended weightlessly, without a body,
in a totally black, silent void.
And unlike meditative techniques, which are so numerous and have so
many variables that it is difficult to subject them to large-scale, objective,
controlled, repeatable scientific studies, the flotation tank is a controlled
and unchanging environment, ideally suited for scientific research. Attempts
to study meditation often must compare groups of subjects engaged in specific
meditative techniques with control groups who are (usually) simply sitting
quietly. But as we have seen, it is often hard to tell if meditators are
truly in an authentic meditative state. However, when using the tank, there
can be no doubts which group is floating and which is not. The result is
that float-tank research produces those things so dear to the scientific
heart-hard data, value-free statistics, replicable objective studies. As
a consequence, there has been a surge of flotation-tank research in recent
years by large numbers of scientists interested in the workings of the
human mind, including cognitive psychologists, neuroendocrinologists, educators,
and psychiatrists. These researchers have produced a comparatively large
body of information about the effects of flotation and sensory deprivation.
Among their findings:
Events which disturb our body's natural equilibrium or homeostasis
are stressful, and as we've noted earlier, stress impairs our ability to
think clearly. One study of schoolchildren cited above shows that children
suffering stress scored 15 percent lower on IQ tests than children experiencing
low stress. Elevated blood pressure also clearly lowers mental performance.
Other studies have demonstrated that stress causes dramatic reductions
in ability to think coherently or creatively, and to perform movements
requiring skill and dexterity.
So it's of enormous importance that a large amount of research, particularly
several series of studies at the Medical College of Ohio, Lawrence College,
St. Elizabeth's Hospital in Appleton, Wisconsin, and the University of
British Columbia, demonstrate that floating has a dramatic stress- reduction
effect. Among the findings are that periodic floats reduce heart rate,
oxygen consumption, and the levels of stress-related biochemicals in the
bloodstream, including cortisol, ACTH, lactate, and adrenaline. The studies
show that floating not only reduces these biochemicals during the float
period, but also keeps the levels low for days and in some cases weeks
after the float session. Because of an apparent vasodilatory effect (that
is, blood vessels and capillaries are caused to relax and dilate), floating
not only reduces high blood pressure but speeds and increases the flow
of blood, with its oxygen and other nutrients, to all parts of the brain.
We can speculate that this increased flow of blood to the brain enhances
mental functioning and assists in building new brain tissue and nourishing
neurons, leading to greater dendritic length, increased richness of dendritic
connections, and increased thickness and weight of the neocortex. An enriched
flow of blood is essential to protein synthesis, and since recent findings
by neuroscientists have shown that memory formation is dependent on protein
synthesis in the brain, we can also speculate that this blood-enrichment
effect of floating enhances memory formation.
INCREASED TOLERANCE FOR STRESS
All of us are able to withstand or resist certain levels of stress, but
for each of us the level at which stress becomes disruptive is different.
In the words of Yale biochemist Philip Applewhite, "The hypothalamus brain
program that recognizes stress when it comes in over the nerves is certainly
a source of variability. Some people may feel stressed when not much has
happened to them; they have a low tolerance for stress. For others it may
take considerably more stress before the hypothalamus identifies it as
such; these people have a high tolerance for stress." That is, the hypothalamus
acts as a homeostatic mechanism, acting to help the body maintain
its equilibrium in the face of external stress. Some people's homeostatic
mechanism is much more sensitive to stress, that is, some people's homeostatic
mechanism has what is called a lower "set point."
In light of this, it's significant that studies by neuroendocrinologist
John Turner and psychologist Tom Fine at the Medical College of Ohio indicate
that floating not only significantly reduces the levels of stress-related
biochemicals, but also has what Turner and Fine call a strong "maintenance
effect" - the lowering of the stress biochemicals continued for many days
after the subject's last float. This has led them to conclude that floating
can "alter the set points in the endocrine homeostatic mechanism so that
the individual would be experiencing a lower adrenal activation state.
It would essentially be associated with a greater degree of relaxation".
This is striking, since it means that the beneficial effects of floating
are not just temporary, but alter the metabolism (or homeostatic set point),
essentially damping down the fight-or-flight response. This means that
levels of pressure that might once have disrupted your ability to think
clearly and perform effectively will seem less stressful after floating.
That is, floating is a way of increasing our tolerance for stress.
We all know instinctively that peak mental performance flows from relaxation,
since our descriptions of peak moments of mental clarity and creative flashes
emphasize effortlessness, fluidity: problems that we have strained over
for months suddenly resolve themselves in a moment of release, and we say,
"Why didn't I see it before - it's so easy!" By comparison, those who are
mentally struggling are a study in muscular tension - they writhe in their
chairs, grimacing, contorted. Also, as we've seen, studies of "twilight
learning" or "Superlearning" show that we are best able to assimilate new
information and think clearly when we're relaxed.
But good relaxation is hard to find. Relaxation techniques such as Progressive
relaxation, Autogenics, and meditation take effort and discipline, with
no assurance of success. In fact, many authorities now believe that most
of us have never experienced complete relaxation in our lives, so we have
no real conception of what it feels like, and no idea of how to cause our
bodies to create that state.
In the warm Epsom salts of the float tank, however, free from the tug
of gravity, your muscles unfold like Chinese Paper flowers in water, growing
supple and pliant. Several studies have used an electromyograph (EMG),
which measures muscular tension, to compare groups who simply floated with
groups of nonfloaters who relaxed by using various relaxation techniques.
In every study floaters quickly became far more deeply relaxed than the
nonfloat groups. Significantly, this reduction in tension persisted, according
to one study, for up to three weeks after a float.
In fact, all evidence indicates that floating actively and automatically
triggers the mirror image of the fight-or-flight response, the relaxation
response. This reflexive response includes reductions in heart rate,
blood pressure, alterations in brain-wave, muscular relaxation, decreased
oxygen consumption, decrease in stress-related biochemicals, and increased
secretions of biochemicals that fill the body with a sense of well-being,
pleasure, safety, and mental clarity. If the fight-or-flight response is
one of spending energy and acting, the relaxation response is one of saving
energy and thinking. Research indicates that floating activates this healthful
response effortlessly. According to Fine and Turner of the Medical College
of Ohio: "These (other relaxation) techniques have the individual elicit
relaxation utilizing some internal strategy with or without external feedback
as to the success of the strategy. In contrast (floatation tank) relaxation
utilizes an environment to induce relaxation with the individual passively
experiencing the process... The controlled repeated experiences of this
effortless passive relaxation provided by the tank may provide an advantage
over these other methods requiring a trial and error approach to the deep
In their continuing inquiries into the psychobiological effects of floating,
Fine and Turner found that a session in the tank dramatically reduced pain
and often induced a feeling of mild euphoria. They experimented further,
using subjects who suffered from severe chronic pain. The results were
exciting. Fine told me that "virtually all of our chronic pain patients
have said that during the flotation period they have lost awareness of
their pain." Wondering what this pain-relief mechanism might be, they set
up a double-blind experiment in which one group received the endorphin
antagonist naloxone. The other group received only a placebo, The study
showed that 100 percent of the subjects were able to tell whether they
had received the endorphin blocker or not. The implications are that floating
stimulates the body to release endorphins, and that the increased levels
of endorphins caused by floating are the cause of the pain reduction and
feelings of euphoria. As we have seen earlier, endorphins are intimately
related with a variety of brain-mind functions, including memory and learning.
It's possible that by stimulating our natural reward systems, increased
endorphin levels might assist in putting floaters into an ideal state for
INCREASED THETA PRODUCTION
Partially as a result of the deep relaxation floating induces, floaters
experience an increased production of theta waves. One study by Gary S.
Stem of the University of Colorado at Denver found that "the significant
effect of floating ... indicates that individuals who had floated in the
isolation tank for one hour significantly raised their theta level." The
intriguing and mysterious theta state, on the threshold between the conscious
and the unconscious, is characterized by vivid, unpredictable imagery,
spontaneous memories, Eureka moments when creative ideas and solutions
to problems appear suddenly, and feelings of serenity, euphoria, and peace.
It is also, as indicated by studies such as those of biofeedback expert
Thomas Budzynski of the University of Colorado Medical Center, a "twilight"
state when the brain "has these properties of uncritical acceptance of
verbal material, or almost any material it can process. What if you could
cause a person to sustain that state, and not fall asleep?" asks Budzynski.
"I believe flotation tanks are an ideal medium for doing that."
INCREASED ACCESS TO THE RIGHT HEMISPHERE
Research also indicates that floating increases the power of, or increases
the floater's access to, the right brain. Thomas Budzynski, who is engaged
in EEG measurement of the hemispheres under varying conditions, asserts
"In a float condition, left hemisphere faculties are somewhat suspended
and the right hemisphere ascends in dominance." Or, Budzynski says more
bluntly, "The right brain comes out in that float tank and says 'Whoopee!'"
Budzynski , with many other brain researchers, believes that this increased
access to the right hemisphere can lead to enhanced learning abilities.
Says Budzynski, "Get access to the right hemispheres of individuals very
quickly, and keep them in that state, and that's where a lot of work
gets done very quickly. We get at this same place with float techniques,
'twilight learning,' subliminal processing, hypnosis, all of these."
There is now overwhelming evidence that floating enormously increases suggestibility;
that is, whatever information you receive while in the tank, whether in
the form of suggestions made silently to yourself or as audio or visual
information presented to you while floating, is accepted fully. In part,
this is due to the altered brain-wave states mentioned above - increased
theta, greater direct access to the right hemisphere, and hemispheric synchronization.
Another explanation is the "stimulus hunger" effect - in the absence
of external stimulation, the RAS "turns up" the brain's volume control
and the brain becomes '"hungry" for information. So when it's given a message,
it accepts it totally. Another explanation is that the part of the brain
in charge of reality testing, critically evaluating incoming information,
is turned off in the restricted stimulation environment of the tank, so
messages can bypass the usual censor of filter and enter directly into
the subconscious. In fact, Dr. Lloyd Glauberman, a New York City therapist
with many years of experience in the use of hypnosis, who is now using
float tanks equipped with in-tank speakers for training athletes and altering
behavior patterns, told me that "the float tank is much more powerful than
hypnosis - simply floating, without inducing a trance, makes you more suggestible
than hypnosis." Studies at the University of British Columbia and elsewhere
indicate that these in-tank suggestions have a unique "maintenance effect,"
retaining their power for months and, in several studies, years.
Scientists estimate that well over 90 percent of the brain's energy is
expended processing external stimuli - visual and tactile information,
gravitational forces, and so on. Freed in the tank of external responsibilities,
the mind turns inward, and subtle mental processes which are ordinarily
drowned out in the clamor of external stimuli gain remarkable force and
clarity. One of these is internal imagery.
The ability to create and manipulate internal imagery, called visualization,
is one of the most powerful learning techniques at our disposal, increasing
our ability to solve problems by "seeing" them in a new way, increasing
our ability to remember by associating nonvisual information with visual
cues, and, perhaps most important, enabling us to vividly rehearse or experience
events mentally. Many studies have shown that an image held vividly in
the mind tends to be perceived by the subconscious and the body as being
real. Visualizing yourself skillfully performing some action, whether delivering
a speech, hitting a perfect tennis backhand, or solving some problem, can
be as effective as actually performing the action. The problem is that
most of us find it hard to visualize performing a feat with the kind of
total concentration and clarity necessary to convince our body it's a happening.
In the tank, however, you are free from all distractions and light.
According to Dr. Glauberman, "Your ability to visualize is much more powerful
while you're floating than it is even in hypnotic ice. Imagery seems more
real, more dreamlike. Most of the time you're actually in the experience."
Dr. Rod Borrie, a New York City cognitive therapist who guides his clients
through in-tank visualizations to help them increase learning, improve
athletic and work performance, and change behavior patterns such as smoking
and overeating, explains the effect in terms of information theory "The
brain," he says, "can process only about seven bits of information at one
time. Complex movements, such as athletic movements, are made of far more
than seven bits of information at a time. Visualization puts all those
bits in one chunk, like putting together a bunch of random letters, which
would be impossible to remember, so they form a single word, which can
be easily remembered. While floating, you put many actions together into
a total image, so when the time comes to actually perform, the entire action
is 'remembered' as a single image."
Just how real this "memory" can be is attested to by javelin thrower
David Schmeltzer of the New York Pioneer Track Club, who uses in-tank visualization
to "watch" himself throwing perfectly. Recently he surpassed his personal
record by several feet, and recalls, "When I released the javelin on that
day it was like deja' vu. At the point of release, I said, 'I know
this throw, I've thrown this throw before!'"
The power of previsualization is not limited to relatively short actions,
but can be used to rehearse mentally or "program" yourself for enormously
complex situations with virtually infinite variables. For example, Bob
Said, a former Grand Prix sports-car champion, who has led two Olympic
bobsled teams and five U.S. World bobsled teams, described to me how he
clearly visualized every foot of the bobsled run as he floated each morning
while training for the 1984 Winter Olympic trials. "In the sled," he said,
"you know where you want to be in each corner but often you find yourself
someplace else. So you try to visualize all the different ways you can
get into each corner, so that when you get into the corner you're already
programmed for coming out." In sports, as in many life situations, we need
to act rapidly, almost automatically. But too often we're paralyzed by
the need to stop and think. For Said, the "muscle memory" that comes from
repeated visualization frees him from that need: "If you have to think
a reaction in the sled, even if you have the world's fastest reactions,
you're too slow. The 'cleaner' you are, the faster you are. I'm definitely
sharper from floating, but it's not a sharpening of abilities so much as
it's allowing one's abilities to function the way they're supposed to,
by getting rid of the clutter."
According to Borrie, who has worked with Glauberman in training a number
of top-flight athletes by using in-tank visualization, "Every athlete we're
working with who has competed has set a personal record. And they keep
on setting them. It's just a very, very powerful tool." "Phenomenal," agrees
Glauberman, "and it hasn't even begun to be tapped yet." They both emphasize
that such learning through visualization is not limited to athletic performance
- mental rehearsals like those of Said can be equally effective in complex
situations such as performing surgery, giving a speech or presentation,
or performing a role in a play or ballet.
ENHANCED LEARNING AND CREATIVITY
The close relationship between learning and visualization is pointed out
by a recent large-scale, rigorously controlled study at Texas A&M,
where chemistry professor Thomas Taylor tested two groups on their ability
to learn and think. One group listened to specific lessons while relaxed
in a dark room, the other while in the tank. Afterward, the groups were
hooked up to an EEG and tested on how much they had learned. The learning
was evaluated on three levels of increasing difficulty: simple memory or
rote learning; the ability to apply the information to new situations and
problems; and "synthesis thinking," the ability to combine the ideas learned
in new and creative ways.
The results were startling. The float group learned significantly more
than the nonfloat group on every level; but most important, as the degree
of difficulty and complexity of the learning task increased, the superiority
of floaters over nonfloaters increased sharply. Concluded Taylor, "There's
no question that the [float] group learned more, but where they learned
is the most important point. People who floated learned at a different
cognitive level. The results show that the more difficult the concept,
the bigger the difference in the performance of the two groups."
Interestingly, Taylor had tested the subject groups to see which were
"visualizers" and which were "verbalizers," and concluded: "When the same
learning records are analyzed on the basis of persons who are basically
"visualizers" versus those who are primarily "conceptualizers" (nonvisual
thinker), a greater degree of learning occurred in the visual than in the
nonvisual group." While the number of visualizers in both groups was equal,
Taylor noted that the float group appeared to visualize better than the
nonfloat group. The EEGs indicated that the float group also produced significantly
higher amounts of theta waves, which are associated with strong mental
imagery. In summary, visualization enhances learning at all levels, floating
increases visualization, floating's enhancement of ability increases as
the complexity and difficulty of the material being learned increases,
and floating sharply increases the ability to think creatively and synthetically.
Floating seems to enhance mental functioning and open pathways of interaction
between mind and body in so many ways that researcher Tom Fine of the Medical
College of Ohio has called it "a breakthrough tool in psychobiology."
TANKS FOR THE MEMORIES: USING THE TANK FOR LEARNING
Studies like the one at Texas A&M have convinced many scientists and
educators that the tank can be a potentially revolutionary tool for accelerated
learning, and tanks are now being used for that purpose at schools, universities,
and over 250 float centers throughout the US, Canada, Europe, and Japan.
As research and popular use increase, it's becoming clear that the float
tank can be used to enhance learning in a number of ways.
The most obvious method of using the tank is to profit from the deep relaxation,
increased theta waves, heightened suggestibility, and increased ability
to process information induced by floating and present the floater with
the information to be learned while he or she is actually in the tank.
This can be done with simple self-suggestion or visualization, the user
choosing appropriate messages and images much as is done in ordinary self-hypnosis.
Virtually all float tanks being produced today are equipped with in-tank
speakers, so that floaters can record the information they wish to acquire
on an audio tape to be played to them while they float. Users have reported
excellent results in learning everything from new languages to prepping
for law, medical, and real estate exams. Language students, for example,
have reported that they are able to acquire several hundred new words in
a single one-hour session, with a retention rate of almost 100 percent.
Most tank manufacturers now sell tanks with video monitors attached,
so that floaters can relax until they are in a suitably receptive state,
then turn on color videocassettes of visual material to be learned. Most
commonly used thus far are commercially produced tapes of professional
athletes playing at the peak of their form, demonstrating sports that include
golf, tennis, running, downhill and cross-country skiing, racquetball,
auto racing, soccer, baseball, basketball, football, sailing, and bowling.
In a golf or tennis tape, for example, each type of swing is reproduced
dozens of times for repetitive visual and sensory stimulation. The images
are enhanced by sound - the solid sound of the club or racquet hitting
the "sweet spot" - and computer-enhanced sequences that electronically
highlight the flowing physical movements. Float-tank research at Stanford
University indicates that watching such perfect performances has a "modeling"
effect, causing you to absorb the movements in what has been called muscle
memory programming, so that when you climb out of the tank the actual
feel of the movements has been assimilated by your body. Watching a one-hour
cassette is thought to be the equivalent of many hours of ideal physical
Many athletes have made their own tapes. Professional football player
Rafael Septien, a field- goal kicker for the Dallas Cowboys, is one example.
Each day he climbs into the tank and watches images of himself kicking
field goals. He credits this use of floating with helping him become an
All-Pro kicker. "There's no doubt the tank is powerful," he told me. "They
say that practice makes perfect, but actually it's perfect practice
makes perfect. That's what you visualize in the tank - perfect practice."
Other tapes have used the modeling effect to help train surgeons, musicians,
salespeople, performers, visual artists, teachers, scientists, and business
executives - whatever can be presented visually can be effectively presented
to a floating learner. Says one maker of such training tapes, "Through
recent advances in the neurological sciences, computerization, and solid-
state sensing devices it is now possible to electronically transfer skills
encoded on video software to the human nervous system." The possibilities
of combining sight and sound seem virtually limitless and are only beginning
to be explored.
One of the most widely noticed effects of floating is a feeling of mild
euphoria, mental clarity, and sensory acuity that lasts many hours, even
days, after leaving the tank. The euphoria can be explained by the continuing
deep relaxation and the increased flow of endorphins and perhaps other
peptides. The mental clarity is largely due to the alteration in brain
waves - slower frequency, higher amplitude, more hemispheric synchronization
- that studies indicate also continues long after emerging from the tank.
The sensory acuity - floaters speak of finding colors brighter, richer,
more saturated, of seeing more sharply, hearing more clearly, having intensified
senses of touch and smell - seems to come from having allowed the senses
to take a short vacation. They return to the world refreshed, having been
what psychologist Arthur Deikman calls "deautomatized" with their doors
of perception cleansed. As an example of how floating can sharpen the senses,
consider recent research indicating that after only one minute of total
darkness the eye's sensitivity to light increases ten times: after just
twenty minutes it increases six thousand times: and after forty minutes
- less time than most people spend in a flotation session - the eye reaches
its limit of sensitivity to light, becoming about 25,000 times more sensitive
than before the exposure to the darkness.
This enhancement of mental and physical functioning makes the hours
after a float ideal for learning of all sorts, since the mind is extremely
receptive to external information, yet still in a somewhat free-floating
state that is conducive to imaginative and creative thinking. Many floaters
find that it is in the hours after a float that they find themselves discovering
solutions to problems or being seized with new ideas, and often notice
that this is a time when reading, studying, listening to music, and so
on are particularly rewarding and productive.
While I was interviewing floaters, one man mentioned to me a "strange experience"
he had while learning Dutch. On one occasion he went in for a float immediately
after his lesson. For various reasons he didn't have any time in the next
few days to review the lesson, but when he went in for his next lesson,
he found that he had virtually total recall of the last lesson, and his
instructor remarked that he must have studied very hard in the interim.
He felt that somehow the float had subconsciously solidified the information
in his brain. Was this possible? he wondered.
Shortly after that I was reading some reports of sensory-restriction
research and read of a study in the early 1960s in which researchers read
a lengthy passage from Tolstoy's War and Peace to two groups of
subjects. They did not tell the subjects to remember this passage: in fact,
it was just one of a number of events that occurred prior to the experiment.
The subjects did not expect a retest. One group was a control group, and
went about its normal activities: the other group spent a period in a sensory-restriction
chamber. After twenty-four hours the two groups were retested. The researchers
found that while there was a significant drop in retention for the control
group, there was none for the experimental subjects. In fact, the
sensory-deprivation group remembered more after twenty-four hours
than at first! In interviewing the subjects, the researchers found that
none of them had expected a retest, and only one had reported that he had
even thought about the passage from War and Peace during the interim.
The researchers dubbed this the "reminiscence effect." Somehow, simply
being in a state of sensory restriction caused an increase in memory.
A recent series of experiments has cast some more light on this curious
reminiscence effect. Subjects were given information, then one group consumed
several ounces of alcohol - not enough to cause inebriation, but enough
to put the subjects into a relaxed and somewhat euphoric state. The control
group consumed no alcohol. When the two groups were later retested, it
was found that the alcohol group had significantly greater recall of the
How to explain? Well, scientists now agree that there are at least two
types of memory, generally known as short-term memory (STM) and long-term
memory (LTM). When we are aware while driving of how many cars are behind
us and how close they are, this is information being held in STM - ten
miles down the road we will have forgotten it. When we look up a phone
number and hold it in our minds for a few moments required to make the
call, this too is the STM at work. STM, in short, deals with information
we need to hold in our minds temporarily, but which is quickly forgotten.
On the other hand, there is another type of information that can be held
in consciousness just as fleetingly as, say, that telephone number, but
can become so permanent that it can be recalled with absolute clarity a
lifetime later, such as the memory of some brief event observed momentarily
by a child but remembered ninety years later. This is information that
has passed into LTM.
Studies using drugs that inhibit protein synthesis in the brain have
proved that short-acting electrochemical changes in the brain represent
STM while protein synthesis in the brain is necessary for LTM. When drugs
that inhibit protein synthesis in the brain are given soon after subjects
learn something, the information is forgotten - that is, it never makes
it into LTM. However, when the drugs that inhibit protein synthesis are
given more than an hour after the learning, the information is not forgotten,
which means it has become a part of LTM. In other words, information passes
in LTM- protein synthesis takes place in the brain - during the hour or
two after the information is received.
One type of protein synthesis in the brain is structural growth: the
growth of neurons, increasing numbers of glial cells, lengthening of dendrites,
formation of new dendritic spines and synapses. As we have seen, this type
of protein synthesis was first detected by Mark Rosenzweig, Marian Diamond,
and their colleagues at UC Berkeley. They found that rats exposed to enriched
environments exhibited heavier and thicker cortical layers, composed of
larger neurons, more glial cells, longer dendrites, and more dendritic
connections. Later studies have shown that even a few minutes of environmental
enrichment are sufficient to cause permanent brain growth: that is, a brief
experience of stimulation can result in protein synthesis. A study by William
Greenough of the University of Illinois have shown that rats trained to
run a maze show dendritic growth immediately after the training. That is,
brain growth is specific response to learning.
Learning and long-term memory can occur only when protein synthesis
takes place in the brain. Protein synthesis in the brain is a direct result
of learning. That is, brain growth facilitates learning and memory on the
one hand, and learning and memory lead to brain growth on the other hand.
Memory and learning, in other words, cannot be separated from physical
brain changes. Rosenzweig and colleagues proved that environmental enrichment
leads to physical brain growth and increased memory and learning. Now we
see that physical brain growth is essentially identical with the process
of learning and increasing memory stores. To use Prigogine's terms, as
energy enters the system in the form of new information or experiences,
it can only be incorporated by means of actual change in the structure
and organization of the system, that is, by brain growth. If something
happens to stop this brain growth, such as administering a drug to inhibit
protein synthesis, the new information that has entered the system will
disappear, be forgotten. However, if sufficient time is allowed for this
protein synthesis to take place, permanent changes will have taken place
in the brain, and the information will be a part of long-term memory.
To return to the "reminiscence effect" noted by sensory-deprivation
researchers, we can surmise that this effect results from the fact that
after being given the information, the sensory- restriction group was removed
for a period from new sensory input, from things that would compete with
the information for long-term memory: Similarly, the alcohol group remembered
more because in their slightly tipsy state they turned their brains off
to potential new information to be remembered, thus giving the original
information sufficient time to "solidify".
It seems clear that this reminiscence effect can be put to good use
by floaters. Whatever information they want to put into long-term memory
should be studied immediately prior to entering the tank (or should be
presented via video or audio tapes during the early part of the float).
The period of sensory restriction that follows - ideally at least an hour
- should allow time for the necessary protein synthesis to occur in the
brain to permit the information to become consolidated and committed to
Also, a number of float-tank studies have made it clear that floating
has a vasodilatory effect, relaxing the tiny capillaries that carry blood
into and throughout the brain. This results in a greater supply of blood
to the individual neurons in the brain. Since blood carries the nutrients
essential for protein, increased blood flow to the brain can only enhance
protein synthesis. In the words of Dr. Arnold Scheibel, professor of medicine
at UCLA and an expert on brain growth, "if there is a bottom line, it is
that no neuron is healthier than the capillary that supplies it. And we
have a very strong feeling that in the capillary supply system is the story
of the maintenance or the slow decline" of the brain. The vasodilation
that takes place while you are floating, then, facilitates brain growth,
which means that by increasing blood flow to the brain floating can facilitate
learning and the formation of long-term memory.